How does 7hp=220lbs??

Until recently, even a shell was rather expensive. From there, I think there is a perception that (a) it is not THE car to have and (B) development of a BMW, and repairs (panels, etc.) are not cheap. I think that probably explains a lot about why you don't see many Z3s out there.

But the fundamental point is that just because there aren't a lot of people running a car doesn't mean it is misclassed. I can throw back 100 examples from you from the ITCS of properly classed cars that people don't CHOOSE to run.
 
Go back and dig up Keith Thomas (Chet Whittel's crew chief on the ARRC winning ITS BMW and 240z) posts on finding horsepower in handling. He seemed to think it was more critical initially than a maxed out engine program (by the way, the finished 2nd at the ARRC in ITS with 170 crank hp, or about what Rob's Z is making) and my experience has been the same. Getting the power DOWN is as important as getting the power.

A couple years back I was in "my car sucks and is misclassed" mode and could dream up all kinds of reasons why that was the case. A lot of engine development, suspension work and TEST TEST TEST has gotten me and the car competitive. And STILL a long way to go.

Until you fully understand the testing and development that goes into winning IT programs in a competitive division, it's really difficult to have a conversation that focuses solely on the factors that you are bringing up.

Based on the raw numbers I see for the Z3, the car looks like it has a chance, but may not be "the" car to have in ITA. That doesn't mean it can't win if prepped and driven to the max. But I suspect that even if you got your weight break you wouldn't see the gains you expect.

My car is also viewed as, hell laughed at by some, a car that doesn't really have a chance in S. I'm getting to where I'm starting to prove people wrong. If I may make a suggestion, focus on the cars strengths and finding ways to maximize them. It seems you have quite a bit more torque than the Miatas and CRXs (and maybe the Integras?), plus what appear to be great brakes. Work on maximizing those advantages.
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Kieth's car has the newer Z-axle that all the e-36 sedans have. He has the ability to tweek the rear suspension. The Z3's tailing arms are non-adjustable, you have to weld on the sub-frame to add adjustors which is truly questionable legality. No really, Jeff I'm telling you it does suck and needs help.

James



Until recently, even a shell was rather expensive. From there, I think there is a perception that (a) it is not THE car to have and (B) development of a BMW, and repairs (panels, etc.) are not cheap. I think that probably explains a lot about why you don't see many Z3s out there.

But the fundamental point is that just because there aren't a lot of people running a car doesn't mean it is misclassed. I can throw back 100 examples from you from the ITCS of properly classed cars that people don't CHOOSE to run.
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In this case Jeff, I'm including all the four cylinder BMW's in ITA, not just the Z3, but it's the only one to have a chance at making weight.

James
 
I'm WITH YOU on the Miata (James) - I think it's wrong but that's another topic.

Out of curiousity, how many days of testing has the car seen since it was built? Not race weekends or track days - its REALLY slow going to learn anything in those settings.

How many dyno pulls?

K
 
The same goes for the driver. I'm not so impressed frankly with God's racing record. Do you REALLY think that a Randy Pobst quality shoe wouldn't make the car faster...?
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I was discussing this aspect with another racer recently, and the point of Randy Pobst came up...heck would Randy make my car shine ??? (Well, no, I doubt he' even get IN it, LOL...) but if he did, you betcha ....he'd smoke me!

But wait...that's not the entire point! Ever really watch a season of WC (Randy's series) with a critical eye? If you have, you know he's not that fast every time he gets in the same car for the same team!!! And it's not just because of reward weight either. Plain and simple, some days he's not God...some days the cars not right for that track, some days the setups not , well, set up!

This is where the real money gets spent and the real time gets found.

K [/b]
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Also known as the "last second"!


People often come up to me and say something like, "IT is great, but you guys really ought to allow_____" (Fill in the blank, cams, big brakes, alternate heads, etc.)

I smile, and say someting like, "Are you sure?? You want to go to the dyno and test cams?? Remember...it's not JUST cams..it's the cam, and the different exhaust that might be better with THAT cam, and the dfferent ECU tunes you'll be dynoing. Change just that ONE part, and you'll cube the number of dyno runs you'll need to find if you're REALLY getting the absolute most from your package......right??"

Thats the point...there are so many variables.....and really nailing them is the key. Andy has a team that rents Spec Miatas. Given a good driver, those things will set track records...and they do it with not big HP, but with lots of testing and track specific setups. But it didn't happen overnight.
 
No really James, you are not listening. I'm talking about the 240Z with drum brakes, and carbs, all that dinosaur stuff that ran about the same lap times as their E36. Keith will tell you over and over that there is horsepower in handling.

We're coming at this from two different planets. You want a quick fix for a car you want to be competitive, using dubious numbers and -- really -- class killing methods to get there. Arguing about weights and competitiveness THIS WAY is exactly what guys like Kirk were (apparently rightfully so) worried about when necessary subjective factors were added to the classing process.

You guys have yet to even respond to Andy's post on how the Z3 (IGNORE THE MIATA FOR THE MOMENT) weight was developed. There are no obvious errors in it. If I am wrong, show me where they are.

Here's two things I'd like to see:

1. Rob turn some laps in his Z3 at 100 lbs less. I suspect the gains you think will see just won't be there.

2. Have Greg/Andy et. al turn some laps in the Z3 and see if there is an improvement.

I had a fast friend run the Triumph two years ago. Embarassed the hell out of me, and opened my eyes to my own shortcomings. And stopped a lot of my internal "my car is being screwed!" stuff.

And you know what? If at the end of the day, the car is NOT competitive at its process weight...well, that's IT for you. If you build a Z3 because you like the cars, like I built a TR8 cause I liked it (for some ungodly reason), and it is not fast when developed to the max, then, well, the choice you have is to run it as best you can, or go build something faster.
 
I'm WITH YOU on the Miata (James) - I think it's wrong but that's another topic.

Out of curiousity, how many days of testing has the car seen since it was built? Not race weekends or track days - its REALLY slow going to learn anything in those settings.

How many dyno pulls?

K
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Actually Kirk, that's half of my topic. When it's making 5hp more than the predicted based on the highest of the initial factory numbers, the Miata is seeing a gain higher than the norm, that's statistically significant. Andy may protest this, but I think his Dynojet is probably really close to the actual number if he pulled 105hp on it initially, that means he was getting close to the 128hp that his car was classed on, then he pulls 140.7hp -> 171hp at the crank. This would indicate to me given all the adders from Joe that the Miata should weight 2540lbs.

James
 
It's obvious James doesn't respond to anything that doesn't fit his issues. DynaPak to DynoJet. Do the research. I GUARANTEE 135 DP's are more than 140 DJ's...all before 100% optimization. Nobody will convince me a AFPR is as good a PFI. THOSE are the facts.

You don't BACK into minimum weights from singular dyno numbers. You can use them to trend to see if something is REALLY amiss (like the 108hp CRX or the 101hp RX-7, or the 189hp 325 at 2850 etc, etc) and a PCA might be looming - but like I said before, some will make more, some less. Should we back Greg's car through the process with his 165+ dynojets? No. It's been through the process. Did the process fail ITA on his car? Maybe. He won two series, set 3 track records and won the ARRC. Did he do it overnight with less than stellar equipment, prep and driving? No. All that had to come together, and until the SE-R/NX proves to be ruining ITA, it won't get a second look or consideration for a PCA. Something has to be proven - yes, PROVEN to be CRITICALLY wrong with the process numbers in order to move forward with that. It is what it is. I welcome all ya'll to build one of those beauties if you think it's the killer.

I can uderstand the arguements for the 2460 on the Miata. I have stated why it's 2380. But to start throwing around retrocative weights based on one dyno sheet is foolish at best and the day it happens to IT is the day they find a whole 'nother set of ITAC guys.
 
..You guys have yet to even respond to Andy's post on how the Z3 (IGNORE THE MIATA FOR THE MOMENT) weight was developed. There are no obvious errors in it. If I am wrong, show me where they are.

Here's two things I'd like to see:

1. Rob turn some laps in his Z3 at 100 lbs less. I suspect the gains you think will see just won't be there.

2. Have Greg/Andy et. al turn some laps in the Z3 and see if there is an improvement.

I had a fast friend run the Triumph two years ago. Embarassed the hell out of me, and opened my eyes to my own shortcomings. And stopped a lot of my internal "my car is being screwed!" stuff.

And you know what? If at the end of the day, the car is NOT competitive at its process weight...well, that's IT for you. If you build a Z3 because you like the cars, like I built a TR8 cause I liked it (for some ungodly reason), and it is not fast when developed to the max, then, well, the choice you have is to run it as best you can, or go build something faster.
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Jeff,

I uderstand what you're saying. But, here's the error in how the Z3 and all the four cylinder BMW's are classed. They don't make the gains that is predicted by the "formula" What if all cars were assumed to gain the same as the rotary's?? The M-44's come with a nitrided crank, tubular stainless steel headers, and roller rocker arms. You think that by going to a custom header, you're going to see the same gain as going from a cast iron manifold to a custom tube header? As for the rear suspension, we shouldn't be getting the same adder as the sedans with the Z-axle or the Miata for that matter, not when it's non-adjustable and you get the kind of changes in camber and toe that we get. You can set it up hard, but then you loose the rear grip, or you can set it up softer and have it wallow on entry. It's just not as big an advantage as a true double a-arm. Why does Prepared allow trailing arms and solid axles to be replaced by custom fab'ed units?? Because, neither can cut the mustard with a true double a-arm. In reality we shouldn't get the 50lbs adder for IRS either.

James
 
As for the rear suspension, we shouldn't be getting the same adder as the sedans with the Z-axle or the Miata for that matter, not when it's non-adjustable and you get the kind of changes in camber and toe that we get. You can set it up hard, but then you loose the rear grip, or you can set it up softer and have it wallow on entry. It's just not as big an advantage as a true double a-arm. Why does Prepared allow trailing arms and solid axles to be replaced by custom fab'ed units?? Because, neither can cut the mustard with a true double a-arm. In reality we shouldn't get the 50lbs adder for IRS either.

James
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James,

Please read my posts. It's like you glaze over everything. I have no problem expalining decisions or thought processes but if you aren't going to even think about them or read them, then I have to stop.

1. There is no 'adder' for either your suspension or the E36 318. The process is NOT GRANULAR enough to differentiate. They are considered the same. Strut-based RWD platforms.

2. The Miata takes a 50lb adder for it's Double Wishbone set up.

3. You do NOT get an adder for IRS. No car does. The Z3 50 adders is for big brakes - as I have explained.

The process is not perfect. Maybe 50 lbs is too little for double wishbones. Maybe 50 lbs is too much for big brakes, maybe 50lbs is to little for FWD, who knows but it is what it is - and is the reason there are so many different cars that now feel they have a shot.
 
James, look at Andy's post on Rob's power and Dynapak v. Dynojet. It looks to me that the Z3 is seeing a pretty normal gain from an IT build.
 
I REALLY don't want to get into the Miata issue on this thread, b ut there's an obvious parallel... how do any of us know (sorry Andy) that his 140 hp on a DJ is even legal??

It's just ONE example!
 
I REALLY don't want to get into the Miata issue on this thread, b ut there's an obvious parallel... how do any of us know (sorry Andy) that his 140 hp on a DJ is even legal??

It's just ONE example!

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:) It's easy to cheat when everyone assumes you are legal!!! :birra:
 
....
Z3 138HP x 125%=172.5 = 14.5 = 2501 + 50 IRS 2551+ 50 for good brakes 2601.....

Miata 133hp x 125%= 166.2 * 14.5 =2410 + 50 for IRS 2460 + 10 for good package 2470

Not sure you can justify it any other way than to say the cars did not have enough cage to put all the weight on them that they should have gotten if the process was followed....Sorry my friend but facts is facts
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This is where I got a 50lb adder for IRS.

James
 
Exactly. Which is why we are putting a small block Ferd 289 in the Jensen. It will be one HELL of a lap or two.....
 
I REALLY don't want to get into the Miata issue on this thread, b ut there's an obvious parallel... how do any of us know (sorry Andy) that his 140 hp on a DJ is even legal??

It's just ONE example!
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Jake, that's 50% of this thread :lol:

James
 
So on your IT Z3 motor you’ve done the following:

*10.5 : 1 compression (yes, it’ll run on 93 octane, just watch your A/F and timing)
*1mm, 0.040” overbore
*Block bored with torque plate to make sure bores are straight - skip this step and you've lost some power
*Some high quality rings, Total Seal etc. to make the most of the engine specs
*Best aftermarket pistonreplacements for better sealing and construction
*Fabricated oil pan with integrated crank scraper
*Check over the oiling system to see what can be gained there through careful analysis and book adjustments
*Rocker geometry maxed out to get every last 0.001” of valve lift
*Valve job to the max allowable according to BMW’s build specs
*Valve springs selected from a large number to get the highest spec springs in the bunch
*Head port matched, intake port matched
*Stepped header design, multiple configurations tested to get max power/torque in the racing range
*A/F adjustments made with stand alone ECU to make absolutely sure at every RPM point you’re on the money for max power/torque
*Lightest legal flywheel you can do, even a surface skim helps on the weigh
*Lightest aluminum pressure plate you can have made, small light clutch, open and free, lose the weight
*Light damper, under drive pulleys, light pulleys
*Lots of dyno time with your ECU adjusting fuel and timing

And I'm sure some other things that people more learned than I can comment on. I'd say until you've done all of this then you don't have a 100% maxed out IT build. I know I'm not there.

Ron
 
This is where I got a 50lb adder for IRS.

James
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Except that while Joe helped develop the process, he is not on the ITAC and is not 100% in tune with it obviously. I gave you what you needed in post #50.







So on your IT Z3 motor you’ve done the following:

*10.5 : 1 compression (yes, it’ll run on 93 octane, just watch your A/F and timing)
*1mm, 0.040” overbore
*Block bored with torque plate to make sure bores are straight - skip this step and you've lost some power
*Some high quality rings, Total Seal etc. to make the most of the engine specs
*Best aftermarket pistonreplacements for better sealing and construction
*Fabricated oil pan with integrated crank scraper
*Check over the oiling system to see what can be gained there through careful analysis and book adjustments
*Rocker geometry maxed out to get every last 0.001” of valve lift
*Valve job to the max allowable according to BMW’s build specs
*Valve springs selected from a large number to get the highest spec springs in the bunch
*Head port matched, intake port matched
*Stepped header design, multiple configurations tested to get max power/torque in the racing range
*A/F adjustments made with stand alone ECU to make absolutely sure at every RPM point you’re on the money for max power/torque
*Lightest legal flywheel you can do, even a surface skim helps on the weigh
*Lightest aluminum pressure plate you can have made, small light clutch, open and free, lose the weight
*Light damper, under drive pulleys, light pulleys
*Lots of dyno time with your ECU adjusting fuel and timing

And I'm sure some other things that people more learned than I can comment on. I'd say until you've done all of this then you don't have a 100% maxed out IT build. I know I'm not there.

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And again, I am not questioning most of this stuff. Kessler builds some top-quality sh!t we all know. I have to question the lack of PFI if we are going to say it's 100% and should be used at THE benchmark.

ALSO - the Pak to Jet issue is real and unacknowledged.
 
And again, I am not questioning most of this stuff. Kessler builds some top-quality sh!t we all know. I have to question the lack of PFI if we are going to say it's 100% and should be used at THE benchmark.

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Sorry, I must have missed that. I'm just asking an honest question no offense to Kessler (I assume the builder). Just that if you haven't done all that, and some other stuff too I'm not aware of, then you don't have a flat out build.

Be worth doing a lot of other things too like looking at variances in stock cam shafts and getting the best ones, ditto heads as for sure there are some variations there like any other cast and machined part.

I know I've got a long way to go.....

R
 
James, The only issue with the miata weight is that it was based on the wrong weight. If the car makes a little more BFD it is just like weight if its done inside the process we did our best. I am sorry to say this James but you will always be a back marker with a looser attitude that you have. You were beat before you ever bought a car because you didn't want to play by an existing set of rules. Now you would like the process tailored to fit your car because you have not done the work or likely have the skill set to get it to the front. 5 pages of trying to reason and show you that you have work to do is enough. I showed you the math on how the car get to where it is. The is based on predicted not actual numbers. Actual numbers can only come to play in a big error as far as I am concerned. YOu just need to get off the net and go do about 30 driving schools and pay a professional to do your development work and one day you may find yourself at the pointy end of the stick but unfortunately I doubt because I believe you have lost before you even got started....

And Andy is correcrt I am not completely in tune with how the process is being applied, Obvious since I am asking questions about it. But if your not giving 50 for IRS then the z3 comes out at 2551 where does the extra 50 come from. Just like the 240sx where does the extra weight come from?
 
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